Cotton cleaning apparatus



July 11, 1933. J. E. MITCHELL 1,917,896

COTTON CLEANING APPARATUS Filed June 23, 1952 mond-shaped openings therein.

Patented July 11, 1933 i UNITED STATES PATENT oFFIcE Joan E. MITCHELL, or DALLAS, TEXAS common CLEANING APPARATUS 7 Application filed June '23, 1932. Serial myclasw.

"lo forated sheet metal screens now fgenerally employed for thispurpose.

The invent on 1s illustrated in the accompanying drawing, in which Figure 1 1s across-sectional view illus- 15 trating the arrangement of the elements of a cleaning machine constructed according to my invention; j t Figure 2 is a plan View on an enlarged scale of a curved expanded met-a1 screen ele- 2'0 ment and Figure 3 is a development of Figure 2 in cross section taken on the line 33 of Figure 2, with lines thereon indicating the angles of inclination of the walls of the dia- Figure 1 is largely illustrative in character, and is intended to show the relation of a rotary beating cylinder to the screen, and the direction of rotation of the cylinder rela- 30 tive to the screen.

In this view the numeral 1 indicates a casing having an inlet, 2, for the cotton to be screened, a screen, 3, of the expanded metal 7 construction to be referred to, and a beating cylinder, 4, rotating, relative to the screen, in the direction indicated by the arrow.

According to my invention, I utilize for the screen a product known in the art as expanded metal. This product, as is Well known, is made by providing rows of slits or cuts in a sheet of metal in such manner that when the sheet of metal is drawn out from opposite sides it forms into a connected series of diamond-shaped openings, the material between the slits in the metal forming the walls of these openings. The product thus formed may be rolled or pressed into sheet form, but in the particular product I employ, the walls of the diamond shaped open- .by the dotted lines a.

ings are not flattened, but are left to ex-l tend at an angle to the horizontal planeof v the openings.

As illustrated in Figures 2 and the screen 3 presents a series of diamond-shaped openings, 5, having walls, 6, which areinclined to the horizontal at angles indicated The under side of each wall 6 at one side of each opening is connected at its central'portionto the upper 69 side of the central portionof the wall of an adjacent opening, as indicated at 7 ,and as .the upper side of the opposite wall .of this openlng is on the under side of the wall of an adjacent opening, it follows that at each point of connection 7 between the walls of the diamond-shapedopenings, there will be an angular, or, tobe exact, a substantially curved portion, which projects above the" plane of the wallet the opening on the op- 70 posite side, and as the diamond-shaped opens ings are symmetrically arranged, therewill be parallel lines of these curved projections lying on corresponding sides of the openings. These projections are on the far, or

remote side of the openings relative to the direction of rotation of the beating cylinder, which is indicated in Figure 3 by an arrow If a sheet of the metal thus formed be viewed at the proper angle from one side thereof, with the lines of diamond-shaped openings running at right angles to the line of vision, one sees only the edges, 8, of the Walls of said openings, and the openings themselves are free and unobstructed, or of 7 the maximum size. If, now, the sheet be. viewed from the opposite side, one sees the flat sides, 9, of the inclined walls 6 enclosing the diamond-shaped openings, and these latter appear to be as narrow slits, or, at least, of much less extent, or area, than when the, sheet isvi-ewed in the direction first referred to.

Moreover, the uncut portion of the metal connecting opposite sides of a line of diamond-shaped openings produces a construction in which.'in effect, the bottom of the wall at one side of each opening rests upon the top of the wall of the adjacent opening, while the continuation of the Walls in either direction passes under the bottom edges of the walls of two ad acent openings, with result that each opening 1S centrally elevated at the point of connection with the wall of an adjacent openin It is this feature of the screen element, in conjunction with the use of a beating cylinder rotating in a direction to move the cotton against the edges 8 of the openings, rather than in the opposite direction, which wouldcause the cotton to engage the fiat sides 9 of thewalls of the openings, which enables me to secure unusuall hi -h eflicienc in the screenin 0 eration. This is due to the fact that in the movement of the cotton over the screen the trash can readily pass through the openings,

and as the cotton passes over the curved projections at corresponding sides of the diamond-shaped openings the trash will be scraped off of the'cotton and fall through the openings. I I

lVith the above explanation in mind, and by observingthe angles of inclination of the wall 6 of the expanded metal screen, and the stantially' tangential, it follows that the trash may readily enter the openings 5, and

that the cotton is drawn over'the curved,

projected edges of the walls, adhering trash particles will be scraped off of the cotton andifall through said openings, as above. described. r v

It will be apparent to those skilled in the art that while the walls 6 of the screen present quite narrow edges or boundary surfaces to the openings, relative to the direction of movement of the cotton, they are of considerable width when viewed laterally, and hence I am enabled to use a screen of equal or greater strength than thatrequired in a wire screen while "at the same time exposing a vastly less amount of surface to oppose the passage of trash through the openings in the screen. I v

It may be explained in this connection, that inthe use of ordinary wire screens, the wires defining the openings, in order to provide sufficient strength, must be so large or thick that the cotton forced over the screen readily sweeps mostof the trash along with it. In other words, only a small portion of the trash,

' loosened from the. cotton by the action ofthe beating cylinder is discharged through the Q openings between thick wires, and if the open ings are made large enough to permit the freer discharge of the trash, a considerable waste of seed cotton inevitably results.

The same objection to a screen made up of wires also applies to screens made of per forated sheet metal. lhat is to say, the per forations must not only be small enough to prevent the cotton going through, but the metal itself must be of suflicient thickness,

and the metal left between the perforations must be Wide enough to give strength sufiicient to withstand the strain of the heavy stream of cotton forced against it by the beating cylinder. When a perforated sheet ofadequat strength is employed, the thickness of the metal itself, and the Width of the margins between the openings, make it difiicult for the trash loosened by the beating cylinder to find its way out through the openings. Y

In the expanded meta-l screen which 1 cmploy, the metal between the openings being angularly-disposed, by forcing the seed cotton ova-the screen in the manner described, the cotton meets and scrapes against the thin projected edges only of the metal between the openings, andthe'maximum number of open: ings of the proper size is provided for the escape of trash as fast as it is loosened from the cotton by the action of the heaters,

From what has been stated it will be obvious that, the metal itself between the openings can be of any width whateyer necessary to provide sufiicient strength without appreciably diminishing the capacity of the screen or interfering with thefree outlet of trash removed from the seed cotton either by the action vof the beating cylinders or by the scraping action on the thin edges of the screen.

It is important to note, moreover, that the screen offersthe greatest resistance in stifiness or strength when the cotton is forced edgewise against the wallsbetween the openings, instead of fiatwise, which latter occurs in the use of wire or perforated screens, and would also occur inthe use of the screen of this invention if the beaterwere rotated in a direction opposite to that described. Y

It remains to be stated, finally, that the comparatively sharp thin edges bf the proj ected lips of the screen produce no appreciable machining of, or other bad efie'cts upon, the'staple or cotton fibers, in the movement the cotton thereover. son that, while the loosened trash readily escapes through the tangential openings formed by the angular walls, the fibrous nature of the cotton does not permit it to get far enough into the openings to be machined or cut by whipping across the thin edgesof the projected edges of the walls.

'I claim:

1 In a machine for cleaning cotton in com bination with a curved expanded metal screen characterized by diamond-shaped openings bounded on all four sides by walls of greater width than thickness and angularly disposed,- a beating cylinder cooperating This is for the reawith said screen and rotating in a direction to move the cotton into engagement wit-h and over the edges of said walls.

2. In a machine for cleaning cotton'in combination with a curved expanded metal screen characterized by diamond-shaped openings bounded on all four sides by walls of greater width than thickness and inclined at an angle to the horizontal, and the corre spending parts of the walls of all of said openings at one side being elevated above the plane of the corresponding portions of the walls on the opposite side, a beating cylin-' der cooperating with said screen and operating to move the cotton thereover in a direction to cause the cotton to engage the edges of said projecting walls.

3. A machine for cleaning cotton compris-x ing, in combination with a screen made of expanded metal and presenting throughout diamond-shaped openings defined by Walls of greater width than thickness and inclined to the horizontal, and the walls on correspondpanded metal and presenting throughout diamond-shaped openings defined by walls of greater width than thickness and inclined to the horizontal in such manner that the opposed sides of the openings lie' in parallel planes, and the walls on corresponding sides of all of said openings being elevated at the center, a beating cylinder cooperating with said screen and rotating in a direction to move the cotton against the edges only of said inclined Walls in directions substantially" parallel to the planes of extensions of said walls.

In testimony whereof, I have hereunto set 7 my hand.

J OHN 7 E. MITCHELL. 

